As is well known in the art, the indoor coil in a refrigeration system typically is required to be defrosted from time to time. Various devices and methods for defrosting are known.
As is also well known in the art, the more commonly known defrosting methods, electric defrost and off-cycle defrost, have certain limitations or disadvantages. Another known method, reverse cycle hot gas defrost, is less commonly used due to certain disadvantages, including, but not limited to, the following.                In low ambient temperature conditions, the defrost capacity (as hereinafter defined) is too low, often resulting in a prolonged or incomplete defrost.        In high ambient temperature conditions, the defrost capacity may be too high, which could cause thermal shock and/or steaming.        In low ambient temperature conditions, there is a potential for flooding the compressor.        In most existing systems utilizing reverse cycle defrost, a receiver is lacking, or the systems tend to include extensive piping and valves.        Flow reversal frequently results in flooding the compressor.        Reversing valve non-actuation upon flow reversal.        